diff --git a/include/ignition/transport/Discovery.hh b/include/ignition/transport/Discovery.hh
index b673e2ad7..ff3f3f6e1 100644
--- a/include/ignition/transport/Discovery.hh
+++ b/include/ignition/transport/Discovery.hh
@@ -1170,6 +1170,7 @@ namespace ignition
           // Send the discovery message to the unicast relays.
           for (const auto &sockAddr : this->relayAddrs)
           {
+            errno = 0;
             auto sent = sendto(this->sockets.at(0),
               reinterpret_cast<const raw_type *>(
                 reinterpret_cast<const unsigned char*>(buffer)),
@@ -1179,7 +1180,9 @@ namespace ignition
 
             if (sent != totalSize)
             {
-              std::cerr << "Exception sending a unicast message" << std::endl;
+              std::cerr << "Exception sending a unicast message:" << std::endl;
+              std::cerr << "  Return value: " << sent << std::endl;
+              std::cerr << "  Error code: " << strerror(errno) << std::endl;
               break;
             }
           }